Confused, maybe an ORCL DBA can explain
Haven't used Oracle since a RAC fiasco involving cache coherency (or more accurately, incoherency). But IIRC:
- you can tune the SGA to trade memory usage for disk I/O, so that your frequently-hit tables stay in memory. How is that different from this IN_MEMORY option? Is it just a more aggressive hint to the DB that My Particular Table gets first dibs, as opposed to letting the SGA manager decide?
- you could pull tricks outside of Oracle, such as using mmapped files. I suppose that's only useful if your special table is in a file by itself and/or your DB files fit in RAM?
Can someone explain?